On Sunday, July 3, the Odenton Heritage Society will commemorate the beginning of train service on the Amtrak-MARC Penn Line with an addition to the Society’s railroad display. In July 1872 — 150 years ago — steam-powered trains began running between Baltimore and Washington through Odenton. Modernized over the years, this line became a vital part of local and intercity transportation. Train service shaped Odenton’s growth through employment, troop movements, commuting opportunities, and a busy junction with a railroad to Annapolis and Fort George G. Meade. The Society’s museum, which presents 150 years of community history, is located at 1367 Odenton Road. Hours on July 3 are 1 pm to 4 pm, and admission is free.